1. Field of the Invention
The present invention relates to a wireless communication system and, in particular, to a method and apparatus for generating and transmitting multimedia broadcast data in a wireless communication system.
2. Description of the Related Art
Mobile communication systems have been developed to provide the subscribers with voice communication services on the move. With the rapid advance of technologies, the mobile communication systems have evolved to support high speed data communication services as well as the standard voice communication services.
Recently, as the next generation mobile communication system of the 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE) is under development. The LTE system is a technology for realizing high-speed packet-based communication at about 100 Mbps, aiming at commercialization in around 2010. Regarding the commercialization of the LTE system, a discussion is being held on several schemes: one scheme for reducing the number of nodes located in a communication path by simplifying a configuration of the network, and another scheme for maximally approximating wireless protocols to wireless channels.
Unlike voice service, data service is characterized in that the resource is allocated according to the data amount to be transmitted and channel condition. Accordingly, in the wireless communication system such as cellular communication system, a scheduler manages resource allocation in consideration of the resource amount, channel condition, and data amount. This is also the case in the LTE system as one of the next generation mobile communication systems such that the scheduler located in the base station manages and allocates the radio resource. Also, the second layer protocols such as MAC and RLC are supported in the base station.
The wireless communication system such as LTE system supporting high speed high quality service meets the requirements for providing multimedia broadcast service, and thus there are many researches being conducted to provide the multimedia broadcast service in the wireless communication system. The multimedia broadcast service supported in LTE is called Multimedia Broadcast Multicast Service (MBMS) which is provided in such a manner that a plurality of base stations transmit the same broadcast data generated by an MBMS server. In case that multiple base stations transmit the same data, the transmission efficiency on the radio channel increases significantly. As aforementioned, however, since the second layer protocols such as the Media Access Control (MAC) and Radio Link Control (RLC) are placed at the base station, the data generated by the MBMS server are likely to lose data integrity through the second layer process at different base stations.